Synthetic method for antifungal drug intermediate (2R,3S)-1-(1,2,4-triazol)-2-difluorophenyl-2,3-epoxybutane

The invention discloses a synthetic method for an antifungal drug intermediate (2R,3S)-1-(1,2,4-triazol)-2-difluorophenyl-2,3-epoxybutane. The synthetic method comprises the following steps: (1) reacting a compound IV with a Grignard reagent to obtain a compound III; (2) employing a one-pot reaction to react the compound III with trimethylsulfoxonium iodide and 1,2,4-triazole and then react with p-toluenesulfonic acid, so as to obtain a compound II; and (3) reacting the compound II with methanesulfonyl chloride under an alkali condition to generate the target compound I, wherein the Grignard reagent is 2,4-difluorophenylmagnesium bromide or 2,5-difluorophenylmagnesium bromide, and the structural formula of the compound IV is shown in the specification. According to the synthetic route, the reaction conditions are mild and easy to control, the reaction route is simple, the related solvents in the reaction process all are common solvents, the reaction conversion rate is high, and the method possesses extremely high feasibility, is beneficial for industrialized batch production, and possesses extremely large exploitation potential and extremely good application prospect.